40 THE POPULAR SCIENCE MONTHLY 



to a mediocre line having the same average size (and other values 

 which I can not cite here). In other words, the sum of the descendants 

 is identical with the sum of the ascendants. 



Each race differs from the others in form, stature, hardiness and 

 chemical composition. The name population has been given to the 

 mixtures of races, such as nature gives us in a meadow or such as we 

 have in cultivation when segregation has not been carried far enough, 

 that is to say, when pure lines which can be distinguished have not 

 been separated grain by grain. This practise of selection, according 

 to Vilmorin, has already been tested not only in the vast field of theo- 

 retical botany, but also in that of applied botany. At Svalof, Sweden, 

 cereals are selected according to this principle by evaluating the differ- 

 ences by numerical methods. All agricultural Europe follows with 

 special attention the classic experiments of Nilson and his collaborators. 

 Except for the very rare phenomenon of spontaneous variation 

 (mutation) we can by beginning with these pure lines operate in a 

 practical way, with almost mathematical certainty, the probable error 

 being minimal. In cereals, and especially in wheat, the characters to 

 be studied which will be constant for a given race are : stooling, regu- 

 larity of growth (that is, greater or less individual variation), average 

 weight of the grains, resistance of the straw to lodging, length of the 

 straw, form and length of the heads, composition of the grain (starch, 

 sugar, nitrogen, fat, etc.), disease-resistance. In the short time at my 

 disposal I can not explain to you the ingenious methods used to deter- 

 mine with precision these different characters. I wish to add only 

 one thing. Each of these characters or their combination in pairs or 

 groups determines the probability of success and good harvest in a 

 given locality, and, in consequence, the more constant forms, the more 

 pure lines there are, the more prepared will scientific agriculture be 

 to furnish to cultivators races which will suit their soils. Now if you 

 consider that these problems are among those that chiefly interest 

 mankind, which demands each day its daily bread, you will understand 

 that the slightest discovery which makes for the betterment of cereals 

 means a noticeable increase in the wealth of a nation. If France is 

 one of the richest countries of the world it is because her wheat 

 production is superior, in respect to her territory, to that of all her 

 competitors. 



Now, modern agriculture, given new life by botany, has obtained 

 in France, Germany and other civilized countries, a considerable num- 

 ber of these varieties, starting from cereals introduced into our country 

 in the course of the long history of civilization; that is, from times 

 more ancient than any documents written on parchment or carved in 

 stone. 



